FIG. 1 is a flow chart depicting a conventional method 10 for fabricating a portion of a conventional magnetic recording head. More specifically, the conventional method 10 is used for cavity in the portion of the substrate forming the air-bearing surface (ABS). FIGS. 2-4 depict a portion of the conventional magnetic recording head 50 during fabrication. A photoresist layer is provided on the substrate, via step 12. Using photolithography, a pattern is transferred to the photoresist layer, forming a conventional a photoresist mask, via step 14. The mask exposes portions of the substrate, but covers other parts of the substrate. FIG. 2 depicts the conventional head 50 including the substrate 52. A mask 54 has been formed. A portion 53 of the substrate 52 is exposed by the mask 54. With the mask in place, a conventional reactive ion etch (RIE) is performed to form a trench in the substrate, via step 16. FIG. 3 depicts the conventional magnetic recording head 50 during the RIE. During the RIE, part of the substrate in the exposed region 53 is removed. Thus, substrate 52′ is shown in FIG. 3. A conventional cavity 58 has been formed using the RIE. A photoresist strip is performed, via step 18. FIG. 4 depicts the conventional magnetic recording head 50 after step 50 has been completed. Thus, the mask 54 has been removed.
Although the conventional method 10 may provide the conventional cavity 58′ in the substrate 52″, the sidewalls of the conventional cavity 58′ may have a shallow angle. As can be seen in FIG. 4, the cavity sidewalls make an angle θ with the top surface. Typically, this angle is twenty to forty degrees for a twenty to thirty micro-inch depth cavity 58′. In general, the angle θ decreases with an increase in the depth of the conventional cavity 58′. The shallow angle θ may be the result of redeposition 56, shown in FIG. 3. Redeposition 56 results from some of the material of the substrate that is removed being deposited back onto the sidewalls of the photoresist mask 54 and the sidewalls of the cavity 58, as shown in FIG. 3. The shallow angle θ may result in an increase in variations of the fly height of the ABS. Such an increase may make the conventional magnetic recording head 50 more likely to accidentally contact the disk (not shown), which is undesirable. Redeposition 56 may also result in oxidation of portions of the magnetic recording head, such as the write pole. Such oxidation may adversely affect performance and reliability of the magnetic recording head. Accordingly, what is needed is an improved method for fabricating a magnetic recording head.